Pump



C. W. MEADER Feb. 2A, 1954 PUMP Filed April 1o, 195o Patented Feb. 2, 195.4

UNITED STATES PATENT OFFICE Claims priority, application Great Britain May 6, 1949 6 Claims.

The invention relates to pumps which are particularly though not exclusively intended for pumping thick semi-liquid substances, such as mud, bauxite residues, paper pulps, sewage, sleech, cement slurries, unset concrete, oil residues, nlter cake, sludges, clays, silt, pastes, material prepared for the making of bricks, and all materials which are in a plastic state at normal pressures and temperatures. Such thick semi-liquid substances are hereinafter referred to as mud The object of the invention is to provide a pump which shall be capable of pumping muds of various moisture contents, ranging from mud in a more or less iluid state to mud in a stili plastic state.

Forms of pump according to the invention will now be described by way of example, and with reference to the accompanying drawing wherein:

Fig. 1 is a side elevation in section of a pump according to the invention,

Fig. 2 shows the pump in a position subsequent to the cutting movement of the rst cylmder,

Fig. 3 shows a pump in a position subsequent to the pumping movement of the first piston,

Fig. 4 is an end elevation of the pump shown in Fig. 1 on the line IV--IV, and

Fig. 5 is a broken side elevation in section of an alternative form of pump.

Supported on a frame I is a chamber 2 of partcylindrical shape for receiving from a hopper 3 the mud which is to be pumped. One end wall Il of the chamber 2 has an aperture 5 and a tapered pipe 6 extends from said aperture. The end of the tapered pipe 6 is connected to a discharge pipe 'i through a diagrammatically indicated automatic non-return valve il. Around the aperture 5 on the inside wall is an annular seating 9 for the open end I9 of an axially movable cylinder I I. At the other end of the chamber 2 and arranged coaxial therewith and coaxial with the aperture 5 is a second and lixed cylinder I2 which extends outwards from the chamber. The movable open-ended cylinder II is supported in a bearing i3 at the front end of the fixed cylinder I2 the said bearing being arranged in an aperture in the other end wall I 4 of the chamber. The cylinder II is slidable from a position within the xed cylinder as shown in Fig. 1, to a position in which its open end I9 engages the annular seating 9 around the aperture 5, as shown in Figs. 2 and 3.

Within the movable cylinder` i i is a first piston I5. The movable cylinder II is carried on a second piston I 6 movable in the lixed cylinder I2,

2 A piston rod Il for the first piston I5 extends through a bearing I8 in the second piston I6 and is secured to a third piston I9 also movable in the xed cylinder I2.

The second and third pistons are spaced apart in their closest position by a spacer 20 iixed to the piston I9.

The space 2| between the second and third pistons, in the position when the movable cylinder II and rst piston I5 are fully withdrawn from the annular seating 9 as shown in Fig. 1, communicates through a connection 22 with a valvecontrolled supply of operating duid. 'I'he space 23 between the second piston I 6 and the fixed bearing I3 for the movable cylinder communicates through a connection 24 with a valve-controlled inlet and exhaust for operating fluid. The space 25 between the second and third pistons in the position in which the end I0 of the movable cylinder II contacts the seating 9 communicates through a connection 26 with a valve-controlled exhaust for the operating fluid, as shown in Fig. 3. The space 21 behind the third piston I9 communicates through a connection 28 in the closed end 29 of the cylinder I2 with a valve-controlled inlet and exhaust for operating fluid.

In operation, the movable cylinder II and its piston I5 are withdrawn within the fixed cylinder I2 as shown in Fig. 1. Mud is fed from the hopper 3 to the chamber 2. Operating iiuid is supplied through the connection 22 to the space 2| between the second and third pistons, whereby the second piston I6 is moved forwards and the movable cylinder II, secured thereto is moved into the chamber 2 until its open end I9 engages the annular seating 9, as shown in Fig. 2. By this movement the cylinder I I becomes lled with mud.

The supply of operating uid is then cut off and operating fluid is supplied through the connection 28 to the space 21 behind the third pis ton I9 and the space 25 between the second and third pistons is placed in communication with exhaust through the connection 26, The third piston I9 is moved forward driving with it the rst piston I5 within the movable cylinder II.v The iirst piston I5 rams the mud through the aperture 5 and tapered pipe 6 into the discharge pipe l for the mud via the automatic non-return valve 8.

When the third piston I9 has reached its extreme position as shown in Fig. 3, the supply of operating uid to the space 2'! is cut off and the space 21 behind the thirdV piston is placed in comi.

the movable cylinder and the cycle of operations is repeated. When the hopper is full of mud, the q chamber 2 is sealed from the atmosphere, so that when the moving cylinder is1withdrawn from-the aperture after discharge of its load, a partial vacuum is formed, and the contents'ofthe'h'opper are sucked downwards intr.` the chamber ready to be cut into by the moving cylinder during its succeeding forward movement. Y

In effect, the invention provides a pump'with" an inlet valve of maximum cross-sectional area.

'I'he bottom of' the tapered portion of! the inlet to the chamber may be considered as the inlet valve to the pump, and as its area is equal to the projected area of the eiective portion of the cylinder, the area of the inlet valve is therefore, amaximum. The cycle of'operations canv be-controlled from a single rotatable valve as will be understood by those skilled in the art.

,In thealternativeform of pump, illustrated in Fig. 5, the arrangement is similar to that of the pumpY shown. in Figs. l, 2, 3, and 4. The third' piston I9, is, however, supported on a tail rod 30 which is an extension of' the piston rod I1, and

passes throughk an aperture 3l in the Vclosed end 29 of the cylinder, to be carried in a tail rod bearing.32. 'Ihe free end 33v of the tail rod 3B is provided'with a' cam 34, or pushLv plate which may -be used to actuate valves, switchesv or the likeused in the control of the pump.

What I claim is:

1. AY pump for pumping mud, comprisinga` chambery for the mud, said chamber having a Wall with a discharge aperture formed therein, a movable open'ended cylinder of a length atleastas great as that of the chamber axially movable'v through said chamber, aiixed cylinder adjacent said chamber and secured thereto, axedannular. seating disposed inV said wall surrounding saiddischarge aperture, a piston axially movablewithin said. movabley cylinder; fluid. pressure operated driving means to movesaid movable cylinder axially Yfrom a position in which the open end* 0f Vthe movable cylinder is` adjacent one end of Said chamber to a position in which-said open endengages said seating; said driving means-including -a fluid inlet and outlet formed in.r said fixed cylinder, and additional driving means to move said piston axially within said movable cylinder.

2. A pump for pumping mud;v comprising a chamber. forthe'mud having an open inlet and end walls, said chamber having an opening formed in one of said endwalls and a discharge aperture formed in the other of said end walls;

anz axially movable open endedV cylinder of a' length at least as great as that ofthe chamber between the end walls-thereof carried slidably in said zopening, a fixed cylinder adjacent said chainber and secured thereto, a fixed annular seating for the open end ofthe cylinder surrounding said discharge aperture, a piston axially movable within said movable cylinder, fluid pressure operated driving means to move saidmovablecylin-'I der. axially from a position in whichthe open endr-.of the cylinder isv adjacent-one end wall-ot the chamber to 'a position in which said open end 'engages said seating, said driving means including Va fluid inlet and outlet formed in said fixed cylinder, and additional driving means to move said piston axially within said movable cylinder.

3. A pump for pumping mud, comprising a chamber for the mud of.part'cylind`rical shape having an open inlet an'd-'end walls; said' chamber having an opening formed in one of said end walls and a discharge aperture formed in theY other of said end walls an open ended movablel cylinder of a length at least as great as that of` the.v chamber betweenr. the end walls thereof ar rangedV coaxially with the cylindrical part of said chamber'slidably movable in said opening and axially'movable for a distance substantially' equal to the distance between the end walls: thereof a fixed cylinder adjacent said chamber' and'l secured thereto, a fixed annular seating forl the open end of said movable cylinder surrounding saidY discharge aperture, ai pis-ton axiallyl movable vwithin said' movable cylinder, fluid pressure operated driving means to move said movableA cylinder axially from a position in which ,theA

open end of theAmovable cylinder is adj acent one end4 wall of said chamber toa positionin which.r said open end engagessaid seating,.said driving meansincluding a fluid: inlet and outlet formed. in said fixed cylinder,v and additional driving means-'to move said piston axially within said. cylinder.

4..A pump; for pumping. mud comprising a.. chamber for the mud, said chamberv having a wall with a discharge aperture formed' therein,r f an ope -ended cylinder axially:movable` through the chamber, a iixcd annular seating onsaid wall of. the chamber for the open end of the cylinder surrininding. said discharge aperture, a rst pistonaxially movable within thecylinder, a second fixed cylinder, a secondV piston axially movable within saidsecond cylin'denarigid connectionlbetween the seccndpiston and the movable cylinder, a third piston axially movable within; said second cylinder, a rigidconnection between Ysaid first andthird pistons, vmeans to supply pressure duidv alternately to oppositesides. of the second piston, means 'toconnect to exhaust the# side of the second piston opposite toY that connected to the supply of pressure. fluid and'driving meansv to move saidthird piston axially within saidsecondy cylinder andJ the` irst. piston axially withinzthe open-ended cylinder;-

5. A pump for pumping mudY comprising va chamber for the` mud, said chamberv having; a.-

wallv with' a dischargefaperture formed` therein, an open-ended cylinder axially movable throughV the chamber, a fixed annular seating on vsaid wallof thechamber fori the open endof the-cylinder surrounding- .saidY discharge aperture, a iirst piston axially movable within the`v cylinder, af'

second `xedy cylinder, a secondy piston axially` movable Within saidsecond'cylin-der, a rigidcon-A nection-between'the second piston' andthe movable cylinder, a: third piston axially movable 4 within said second cylinder,v a rigid connectionv `charriber for mud of 'part-cy'ir'idric'all shape and..

5 having two end Walls and an open inlet, said chamber having an opening formed in one of said end Walls and a discharge aperture formed in the other of said end walls, an open-ended cylinder arranged coaxially with the cylindrical part of the chamber, slidably carried in said aperture and axially movable for a distance substantially equal to the distance between the end Walls of the chamber, an annular xed seating in the other end Wall of the chamber for the open end of the said cylinder surrounding said aperture, a discharge pipe for the mud connected to said aperture in the other end Wall of the chamber, a rst piston movable within said cylinder, a, second fixed cylinder of a cross section greater than the rst mentioned cylinder and secured on the outside of the chamber, coaxial with the cylindrical part thereof and surroundingr said aperture in the one end wall of the chamber, a second piston axially movable in said second cylinder secured to and closing the outer end of the first mentioned cylinder, a third piston axially movable in said second cylinder beyond the second piston, a rod member passing through an aperture in the second piston and secured at its ends to the rst and third pistons, a spacer member, of a size greater than that of the aperture in the second piston, secured to the third piston on the rod member between the second and third pistons, a plate member closing the outer end of the second xing cylinder, and connections from a supply of pressure fluid and exhausts to the second xed cylinder for moving the second and third pistons therein successively.

CAMPLING WILLIAM MEADER.

References Cited in the iile of this patent UNITED STATES PATENTS Number Name Date 148,819 Gould Mar. 24, 1874 1,795,236 Schupp Mar. '3, 1931 

